Coefficient of Conservatism:
Coefficient of Wetness:
B. S. Walters
Panicum clandestinum of Michigan Flora.
Usually in moist and often sandy ground: floodplains and thickets on stream banks; aspen forests, borders, and clearings; marshy ground, ditches, etc.
Although wide-leaved plants of D. xanthophysum may seem, from the key, rather similar to D. clandestinum, the species are readily distinguished by several tendencies: D. clandestinum has more strongly nerved spikelets than D. xanthophysum, and the leaf blades are more strongly cordate at the base. The panicle, besides having more numerous spikelets, is much more open and lax in D. clandestinum, although autumnal panicles may be mostly or entirely included in the leaf sheaths. The ligule in D. clandestinum appears to be a membranous collar ca. 0.5 mm wide, very minutely ciliate; in D. xanthophysum it is also short, but more clearly a fringe of hairs.
Very rarely specimens of D. latifolium may have the lowermost sheaths ± papillose, but these can be distinguished from D. clandestinum by the fact that the lower internodes of the culm are glabrous, while in D. clandestinum they are pubescent and papillose. The leaf blades in D. clandestinum are very long-tapering with rather straight margins; those of D. latifolium, while ± long-tapering, are somewhat more acuminate. This is a relative distinction that is nevertheless very helpful once one becomes familiar with both species. This is our only species of Dichanthelium that has short-creeping rhizomes and is capable of forming large patches.
The Upper Peninsula collection from along a railway in Gogebic Co., near Watersmeet, is quite far out of range and presumably was introduced.